VEGF dose controls the coupling of angiogenesis and osteogenesis in engineered bone.

Grosso, Andrea; Lunger, Alexander; Burger, Maximilian G; Briquez, Priscilla S; Mai, Francesca; Hubbell, Jeffrey A; Schaefer, Dirk J; Banfi, Andrea et al. · NPJ Regen Med · 2023

basic_science · Level V

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Abstract

Vascular endothelial growth factor-A (VEGF) physiologically regulates both angiogenesis and osteogenesis, but its application in bone tissue engineering led to contradictory outcomes. A poorly understood aspect is how VEGF dose impacts the coordination between these two processes. Taking advantage of a unique and highly tunable platform, here we dissected the effects of VEGF dose over a 1,000-fold range in the context of tissue-engineered osteogenic grafts. We found that osteo-angiogenic coupling is exquisitely dependent on VEGF dose and that only a tightly defined dose range could stimulate both vascular invasion and osteogenic commitment of progenitors, with significant improvement in bone formation. Further, VEGF dose regulated Notch1 activation and the induction of a specific pro-osteogenic endothelial phenotype, independently of the promotion of vascular invasion. Therefore, in a therapeutic perspective, fine-tuning of VEGF dose in the signaling microenvironment is key to ensure physiological coupling of accelerated vascular invasion and improved bone formation.